This invention relates to a surge suppression apparatus. More particularly, but not exclusively, the invention relates to apparatus for suppressing the effects of pressure variations in a liquid, for example paint, supplied under pressure along a supply line by a reciprocating pump.
It is known to provide a surge suppressor which has an air sub-chamber volume which is greatly in excess of the volume of a liquid sub-chamber in order to minimise the differential pressure change experienced in the air sub-chamber resulting from the flexure of the diaphragm due to a change (normally a reduction) in the liquid supply line pressure thereby minimising any surge of the liquid, see for example European Patent Application No. EP 0 707 173 A1.
Such surge suppressors have the disadvantage of being bulky thereby limiting their usefulness in the case of large numbers of suppressors and in working environments with limited space.
It is an object of the present invention to provide a surge suppressor which mitigates this disadvantage whilst maintaining the advantages of the aforementioned known surge suppressors.
According to the present invention there is provided a surge suppression apparatus including a housing, and a flexible diaphragm, the housing being divided into first and second sub-chambers by the diaphragm, the first sub-chamber having connection means for connecting the first sub-chamber to a supply of liquid under pressure, the second sub-chamber containing a gas under pressure and a gas reservoir being in communication with the second sub-chamber so as, in use, to provide an effective volume which is substantially larger than that of the second sub-chamber.
Conveniently said first and second sub-chambers are of similar volume when the diaphragm is in a rest position.
The second sub-chamber is provided with a pressure regulation means. Ideally the pressure regulation means is an active valve pressure regulation means. Desirably the liquid is paint. Desirably the gas reservoir is remote from the housing. Conveniently there is provided an isolation valve between the gas reservoir and the second sub-chamber.